In general, nets are used for fishing or other marine purposes, as well as for recreational and industrial purposes. A weavers knot is commonly used in most net constructions, because it is efficient in knotting ropes together to form a net, both manually as well as automated.
A weaver's knot is disclosed in U.S. Pat. No. 2,804,676.
A disadvantage of nets with weaver's knots, is that the weaver's knot is prone to slipping, resulting in uneven mesh dimensions, and a distortion of the net structure resulting in a reduction of the performance of the net, possible damages and other unpredictable effects. This is especially the case with high performance fibers, as defined below.
Another disadvantage of the weaver's knot when used in fishing nets, is that such a knot, as a result of its size and shape can damage fish, resulting in lower survival likelihood for escaped fish and lower market value for retained fish.
The size and shape of the weaver's knot has the additional disadvantage that it is susceptible to abrasion in the process of being used. When a panel of netting is pulled over a hard surface, the relatively large knots will wear on the limited surface areas of these knots that make contact with the surface and result in a reduced longevity.
Due to the size and shape of the weaver's knot such nets have added drag (resistance) in hydrodynamic and aerodynamic flow. In fishing e.g. this leads to higher energy consumption and CO2 emissions to tow nets and also (especially in the case of fixed net structures) higher reaction forces.
Due to the size and shape of the weaver's knot such nets require substantial rope length to form the knot.
The weavers' knot is relatively big and has a low knot breaking strength which is also a disadvantage because less of the same material would be required to obtain a certain strength if an alternative knot would obtain higher knot breaking strengths.
The various disadvantages of the conventional weaver's knot are experienced not only in nets made from high performance fibers but also in nets made from other fibers including, but not limited to polyamide, polyester, polyethylene, polypropylene, natural fibers, combinations of such fibers, and related products, further referred to as “conventional fibers” in this document.